Question

The molecular electronic configuration of $Be_2$ is:

• A. $ \sigma 1 s^2 \sigma^* 1s^2 \sigma2s^2 \sigma^* 2p^2$
• B. $KK \sigma2s^2$
• C. $ \sigma1s^2 \sigma^* 1s^2 \sigma 2s^2 \sigma^* 2s^2$
• D. none of the above

Answer 1

Answer: (C)

Total no. of electrons in $Be _{2}=8$.
Electronic configuration according to molecular orbital theory:
$\sigma 1 s^{2}, \sigma^{*} 1 s^{2}, \sigma 2 s^{2}=\sigma^{*} 2 s^{2}$